1802, in military writing, for a very tight style of mass marching, from(n.) + (n.).
Lock-step. A mode of marching by a body of men going one after another as closely as possible, in which the leg of each moves at the same time with and closely follows the corresponding leg of the person directly before him. [Thomas Wilhelm, “Military Dictionary and Gazetteer,” Philadelphia, 1881]
Figurative use by 1836.
Online Etymology Dictionary, © 2010 Douglas Harper Examples from the Web for lock-step Contemporary Examples of lock-step
Now, those same resources often work in lock-step with the armed rebellion.
July 30, 2012
Obviously, modern Germans do not march in lock-step like their ancestors.
Leslie H. Gelb
June 5, 2011
Only on rare occasions are there exceptions to the lock-step unity of petrol power.
May 31, 2010
Historical Examples of lock-step
When we go off for lunch, we throw the machines into lock-step.
Alan Edward Nourse
And there was no rising at the tap of the bell, forming in line and walking in lock-step.
Walking in lock-step is not good exercise, and makes the men nervous.
They are not marching in lock-step, but most of them are under guard just the same.
George Helgesen Fitch
We all have to keep the lock-step in business, and business is hell, Evan.